The complex nature of acquired immune deficiency syndrome (AIDS), including homosexual practices and multiple infections, is evident. Whether the almost complete disfunction of the cellular mechanism is the cause or consequence of the infections is a key question requiring high priority answer. Developing an experimental model for exploration of some of those factors involved in AIDS would allow for a kinetic approach and flexibility not available in human experimentation. We are proposing to work on experimental production of immune deficiency in the rabbit whose immunologic parameters are well known and with which we have a lot of experience. Our working hypothesis is that frequent colonic lavages and intrarectal administration of semen for a prolonged period of time can contribute to the induction of immunodeficiency. Adult male rabbits receiving 3 to 4 colonic enemas per week and animals receiving additional intrarectal deposition of homologous semem for a prolonged period of time, together with non-treated animal controls will be examined in a kinetic fashion for changes in : a) relevant serum biochemical constituents (total protein, Alb/Glob ratio, Calcium, Phosphorus, alkaline phosphatase, triglycerides), b) histologic structure of the colon and gut-associated lymphoid tissues (GALT) and c) immunocompetence of the local and systemic immune responses (enumeration of T and B cells, mitogenic stimulation, quantitation of immunoglobulins). The animals will also be monitored for infections to bacteria, viruses, parasites and fungi and for metabolic and miscellaneous diseases. Although the emphasis of this study is on the experimental-induction of immune disfunction, we may anticipate that the spectrum of parameters to be measured will open multiple avenues to study various aspects of the disease and associated infections.